1. Field of the Invention
The present invention relates to a three-dimensional laser beam machining apparatus capable of linearly cutting a so-called long material, such as a pipe and an angle bar, into a free curved shape with laser beams.
2. Description of the Related Art
In recent years, a linear machining apparatus capable of cutting a long workpiece has been proposed. Japanese Patent No. 3769663, Japanese Patent No. 3710116, and Japanese Patent No. 3796079 relate to three-dimensional laser beam machining apparatuses for a long material, the patents of which are held by the applicant of the present invention.
Also, DE19838863A1, DE19721330C2, DE19721331A1, and EP0481462B1 disclose similar machining apparatuses.
These three-dimensional laser beam machining apparatuses require a device for automatically feeding long materials.
The three-dimensional laser beam machining apparatus, which machines long materials having various cross-sectional shapes, requires a loading device capable of loading materials having various cross-sectional shapes.
For the materials having various cross-sectional shapes, such as round pipes and polygonal pipes, the postures thereof around the axis lines are made coincide automatically during the conveyance of materials.
Of these materials, small-size long materials, which are called bundle type materials, are supplied in a bundled state in large quantities.
On the other hand, large, long materials, for example, each having an L-shaped cross section or an H-shaped cross section, which are called versatile type materials, must be set on the loading device one by one with the postures thereof around the axis line aligned.